A serious problem to humans and higher order primates is the accumulation of atheromatous plaque material which attaches itself to the inner walls of blood vessels and begins a build-up of plaque which gradually decreases the available flow passages within, for example, a coronary or other artery. If left untreated, such atheromatous plaque will lead to partial or total blockage of blood flow to the affected portions of the body normally supplied by such blocked or partially blocked arteries. This in turn may lead to serious injury, impairment, or even death.
In cases of serious blood vessel blockages due to build-up of embolic plaque material, the use of one or more methods of removal must be implemented to avoid the need for more life-threatening surgical procedures involving opening the chest for bypass surgery, or the like.
To meet this need, a variety of plaque removal devices have been designed which typically utilize a cutting head supported by an elongated catheter member coupled to a drive mechanism for operating a cutting head. The cutting head is typically composed of a rigid material such as stainless steel or the like which has been impregnated with an abrasive such as diamond powder. The cutting head is manipulated such that the cutting head works to displace the plaque build-up from the inner arterial walls and to crush it into a fine particle structure which may be removed from the circulatory system by the liver.
The effectiveness and desirability of such conventional plaque removal devices is generally limited by two significant problems. First, the use of a sharp high-speed cutting tool inserted within the delicate inner arterial passages exposes the patient to substantial risk of damage to the arterial walls as the cutter operates. In response to this problem, practitioners attempt to provide devices which are safer in operation. However, structures designed to avoid or minimize risk of damage to the arterial walls presented by such cutters usually employ some alignment apparatus which raises the second problem. Such alignment apparatus itself may block or obscure the artery during the procedure and subjecting the patient to further risk and potential injury.
Thus, there remains a continuing need in the art for evermore improved, safer to operate and less injurious emboli cutting catheters which are nonetheless effective in their cutting action.